1.100%silicone rubber . 2.FDA,LFGB,SGS approved . 3.Eco-friendly. 4.Silicone sealing ring. 5.Various designs are available. Silicone Sealing Rings:features:1.100% high quality food-grade silicone rubber .2.Certifications :FDA,SGS,LFGB,ROHS.3.Eco-friendly, waterproof and healthy.4.Heat resistant ,withstand -40~+230 °C.5.Nonstick and durable .Other information :6.Any color and design is available . ...